I've been doing a little work using the DOM and XMLHTTPRequest to load/submit/unload FCKEditor instances within a single page. Haven't looked at it in a couple of weeks, but I wrote up a bit of the work at:

Nice:)I've been using your (slightly modified) function in my recent job. It requires me to first display 'casual' page with sections that become editable when user clicks on one of them. This is done by copying textareas value into empty div on page's load.There is also possibility to unload the editor (or rather brutally wipe it) by creating 'exit' plugin. Code for its Execute method: